Fiber-reinforced fishing rods are generally made by wrapping a tapered steel mandrel with fibers. An epoxy or other curable resin is used as a binder. The fibers and resin may be formed directly on to the mandrel or may be available in the form of a woven or nonwoven matrix which is cut to a suitable pattern and wrapped around the mandrel. The rod is cured as required, after which the mandrel is removed leaving a lightweight, hollow rod blank. The rod blank is then ready for final finishing.
Previous teachings indicate that fishing rods constructed in this fashion are very resilient upon flexing. For example, U.S. Pat. No. 4,043,074 to Airhart shows a hollow rod body composed of a specific arrangement of laminations of a plurality of fiber-reinforced resin plies. The disclosed pattern of laminations results in a rod which resists breakage when the rod is flexed during the casting motion or when a fish is reeled in.
Similarly, U.S. Pat. No. 4,685,241 to Foote et al. shows another fiber-reinforced fishing rod with good bending strength due to a pattern sheet containing a layer of chopped fiber material.
While rods of these structures have numerous benefits, they are still vulnerable to breakage. Breakage is not limited to the exertion of flexing forces. Indeed, the somewhat delicate tip portion of the rod is the most common area of breakage as it frequently encounters external crushing and impact forces. For example, hollow tip rods often break when they are stepped upon or slammed in doors, or if the hollow tip sharply strikes a hard surface. Breakage is also common during shipping as the rod shifts within its container.
Generally, the ease of breakage of any hollow tubular structure is due to the lack of internal support or reinforcement for the exterior surface. In a tapered rod blank, damage is frequently localized to the tip segment because the walls of that portion of the rod are normally manufactured significantly thinner than the walls of the other portions of the blank.